Although not as recognized as human immunodeficiency virus type-1 (HIV-1), human immunodeficiency virus type-2 (HIV-2) also causes acquired immunodeficiency syndrome (AIDS) from the same infection route as HIV-1. Compared to HIV-1, HIV-2 more slowly weakens the human immune system. Moreover, AIDS caused by HIV-2 is less contagious at an early stage, but is more highly contagious at an advanced stage than AIDS caused by HIV-1.
A viral load test of HIV-2 has not been approved by the Food and Drug Administration (FDA). Since HIV, a pathogen that causes AIDS, was first isolated in the early 1980s, diverse research has been conducted into treating AIDS around the world. However, researchers have not succeeded in developing an effective vaccine capable of preventing and treating AIDS.
Since the late 1990s, various types of diagnostic kits to detect HIV have been developed. An immunological method using an antibody that recognizes a specific protein of HIV is one of the most widely used techniques for the diagnosis of HIV infection. Although the diagnostic accuracy of the immunological method using an antibody is high, it requires a large amount of a sample and it is essential to produce unique viral proteins or peptides in each disease in order to produce an antibody required for each diagnosis so that the manufacturing costs for preparing the antibody is increased. Furthermore, it is not easy to preserve and use proteins, and one or a limited number of types of diseases can be diagnosed at once. A method of diagnosing diseases by cultivating cells and using DNA probes can also be used. However, this method requires highly skilled professionals and a great deal of time. In order to overcome these drawbacks, research into various diagnostic kits using polymerase chain reaction (PCR) has been conducted. Demands for diagnostic kits using PCR are increasing due to their high accuracy, simplicity, and rapidity.
In particular, real-time PCR is one of the most widely used methods. Real-time PCR is a method of measuring the accumulation of PCR products in each cycle of PCR in real-time. Using the real-time PCR, fluorescent substances involved in reactions with the PCR products can be detected and the PCR products can be quantitatively calculated. While PCR products are identified using gel electrophoresis after a final stage of PCR is completed according to conventional PCR, real-time PCR does not require post-PCR gel electrophoresis, has high accuracy, sensitivity, and reproducibility, can be automated, can quantify the results, is quick, simple, and biologically safe against dyes such as ethidium bromide (EtBr) and UV irradiation, and can automatically identify amplification of specific genes. Thus, while only qualitative results are obtained using PCR or antigen/antibody methods, quantitative results with high specificity can be obtained using real-time PCR. In addition, since probes labeled with a fluorescence marker are used in real-time PCR, the amount of a sample can be reduced compared to that used in DNA chip and antigen/antibody reactions.
Therefore, there remains an unmet need in the art to both rapidly and accurately detect HIV infection and HIV genotype, and there is an unmet need in the art to develop a method of detecting HIV and a kit for detecting HIV using real-time PCR.